By on August 31, 2016

Boeing 707 water injection takeoff (USAF/Wikimedia]

Bosch, the creator of the horsepower-boosting water injection system in the BMW M4 GTS, will now offer the technology to any automaker that wants it.

Spraying distilled water vapor into an engine’s combustion chamber has an added bonus of greatly increasing fuel efficiency — meaning Bosch might have a lineup at its door when the system enters mass production in 2019, Autocar reports.

BMW was the first customer to use Bosch’s system, adding it to the high performance version of its M4. By reducing engine temperatures and knock, water injection helped push the vehicle’s output from 425 horsepower to 493. Torque saw a similar bump.

The company claims the technology can be used in any vehicle class, from minicar to supercar. The timing is also right, as regulators around the world mandate lower emissions and higher fuel economy.

Water injection is sometimes used on piston and turbine-powered aircraft to improve engine thrust, but Bosch claims the main goal for its automotive technology isn’t power. The company says its system improves gas mileage by 13 percent and reduces emissions by 4 percent. Power levels will rise by 5 percent.

“The system works best on cars with an output of more than 80 kW (107 bhp) per litre,” Bosch global project manager Fabiana Piazza told Autocar. “We’re launching it into the market now as tighter legislation and new real driving emissions tests are increasing the importance of this technology in all cars.”

Piazza said that working with BMW helped refine the technology and bring it to a wider market.

So, how much water would a vehicle equipped with the system use? Not much, Bosch claims. The M4 GTS has a five liter tank in the trunk, but other models could see larger or smaller tanks, depending on vehicle size and cargo space. One tank is good for 1,800 miles, the company claims, and if it runs dry, there’s no problem — only power and mileage will suffer as a result.

One technical issue remains: cold weather, and how to keep the water tank (and lines) from freezing. Bosch is investigating using either engine heat or an electrical system to warm up the system, but hasn’t made a decision yet.

[Image: USAF/Wikimedia]

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74 Comments on “H2Oh Yeah: Bosch’s Power-Boosting Water Injection System Now Available to Automakers...”

  • avatar
    SCE to AUX

    This probably won’t help my Model 3.

    Nice photo, BTW.

  • avatar


    I’ll be waiting for the upcoming proclamation of the aptly-named Watergate scandal.

  • avatar

    “The company says its system improves gas mileage by 13 percent and reduces emissions by 4 percent. Power levels will rise by 5 percent.”

    What kind of compression ratios are they talking? I have a feeling the fuel efficiency gains are from an incremental bump (say, 12:1 instead of 10:1), and that the water injection is used to prevent knock at WOT but unnecessary at part throttle.

  • avatar

    GM figured out how to ensure the system worked in below freezing temps back in the 60’s. Instead of plain old water they used Turbo Rocket fluid.

  • avatar

    In that little conflict started by a guy with a crazy-looking moustache, BMW was using MW 50 (Methanol-Wasser 50)in their engines. The water was added as an anti-detonation additive; the methanol was used to keep the water in the solution from freezing at high altitudes. They must have lost their old design information somewhere in the last 75 years…

    • 0 avatar

      There ya go. I was wondering if anyone would mention water-meth in aircraft.

      For those who don’t know much about flying, it gets really dang cold up there, and stuff will freeze.

    • 0 avatar
      Piston Slap Yo Mama

      Have you been to the BMW museum in Munich? It’s arranged chronologically – with a very curious gap of about six years spanning 1939-45. To say those might be the MOST interesting years would be a gross understatement.

      • 0 avatar

        In those years, BMW was developing and producing its turbojet engine. It wasn’t designed for cars, so it isn’t in the museum. You can see versions of the BMW model 03 turbojet engine in aircraft museums and online.

        AFAIK, BWM couldn’t get the resources to build cars after ’39, and built mostly prewar-designed motorcycles and sidecars during the war, with the turbojet research, already operating in 1938, still getting funding and resources.

        • 0 avatar

          The BMW museum has a room full of turbojet engines used in various aircraft, but no mention of the WWII years, IIRC. They certainly go right around that period, as stated above.

  • avatar

    Pretty cool.

    Some perspective. A short 10 years ago, 300HP + 4 or more seats all but guaranteed a combined fuel mileage in the teens. Now you can get that combo of practicality and performance with legit mixed real world fuel mileage in the mid 20s. This tech could push that into the high 20s. Incredible stuff

  • avatar

    I am glad that you showed a picture of an old KC-135A “water burners “. I’ve worked in -135 engineering for over 25 years. The old water storage area is still on the aircraft. It’s fun trying to explain this area to our foreign customers. Great old aircraft!

  • avatar

    Winter grade windshield washer fluid should work.

    Spitfires has water injection in the 1940’s to give extra short term power.

  • avatar

    Back to the future.

    I had water injection in my 80’s Callaway Turbo VW Scirocco.

    Technically it was window wash fluid, so it didn’t freeze. No intercooler, the car was set for 8 lbs, IIRC. There was a pressure switch that opened at 3 lbs.

    I bought a LOT of window wiper fluid.

    Of course, the window sticker said ” 30 seconds idle down at stop…NO Boost until warm ” You couldn’t expect that from any new car buyer today.

    • 0 avatar

      I experimented with a homebrew system a long time ago and it certainly used a terrific amount of water. Of course I had a terrifically heavy right foot…

    • 0 avatar
      bumpy ii

      These days, the electronically-controlled wastegate wouldn’t let you build any boost until the temperature parameters were met, and the ECU would have a built-in turbo timer.

    • 0 avatar

      +1 For the Hobb Switch & winshield wiper fluid!

      I never took full advantage of the system because I was afraid the nozzle could clog or the pump could fail. Consequently, my tune remained conservative.

      Depending on where it is injected, this may also help with direct injection and carbon build up on valves.

  • avatar

    You REALLY want to see water-injected smoke? Find a photo of a B-52 taking off on alert back in the day – EIGHT ENGINES! Impressive!

    The KC-135s aren’t so bad, either, BTW…

    • 0 avatar

      I was thinking the same thing when I spotted that B-52 in the background of the photo. It reminded me of stories my Dad used to tell me about being stationed on Okinawa while in the Army. He says that he and my mom used to drive down by the end of the runway of a local Air Force base to watch the B-52s take off on their bombing missions to Cambodia (back before the U.S. acknowledged that this was happening). They would park in a tiny Mitsubishi that they owned, and he says that the noise of those 8 engines flying right overhead was unbelievable. Says the whole car used to shake and rock as they went by.

      • 0 avatar

        I was in the USAF 1969-1973 at Beale AFB, 9th SRW Wing Headquarters. The home of the SR-71 – that aircraft sounded like a Saturn V rocket taking off with full afterburners! We also had B-52s and KC-135s. I personally witnessed all that and flew in KC-135s to and from Kadena, Okinawa where B-52s were being phased out to Guam in 1970.

        I know of what I speak!

  • avatar

    How much water is used and how is the water resupplied?

  • avatar

    Are we really going to increase water vapor in the atmosphere to reduce CO2 emissions? Is that the big plan that has the climate change believers feeling optimistic?

    • 0 avatar

      Um, I don’t think that’s what it meant. Any mention about emissions improvement and claims of percentages thereof are just to arouse the green people.

    • 0 avatar

      Well, you have made it known in the past that you don’t believe in climate change and all that stuff, so there is that.

      But it is true that water vapor is a greenhouse gas. The minor detail there is that water vapor doesn’t have quite the detrimental effect that runWay methane, CO2, and NOx emissions do. It’s a chemistry and physics thing, so if you are not into those, it doesn’t matter what anyone says.

    • 0 avatar

      Jeez.. another way all those billions of sweaty people are destroying our Earth! They don’t even need unregulated industries to do it.

      • 0 avatar

        Is it possible to ever have a discussion without the ideology lurking behind each and every point? People sweating does increase water vapor, but the strawman is invalid on so many fronts. Try harder.

        The use of political ideology/parties to justify an opinion on a clearly non-political issue is a dead giveaway of a very weak argument. Good luck with all that.

  • avatar

    This is late to the party. Water injection schemes have been around for some time. It would have been awesome if they looked at those seriously way back when, especially 6 stroke systems, rather than letting some guy in a garage play around with a single cylinder engine (nothing wrong with that, but it does require quite the R&D capital to solve the various issues and make it commercially viable).

    It would have been a great transition technology to have in mature format right now, while we are trying to hammer out grid issues etc.

    Obviously there was no money to be made in waste-heat reduction or someone would have brought this to the market. Put some fire under the automakers’ butts (via higher fuel economy requirements, etc) and low and behold we could eventually see ICE powertrains that waste far less fuel on making waste heat.

    I am curious to hear where they expect this to gain more traction. Perhaps in the transportation sector.

    • 0 avatar

      Commercial aviation, for its part, stopped using water-meth long ago. Engines have been developed that make the rated power without the extra hassle, weight and expense of a water meth injection system.

      I doubt it will take off for cars (no pun intended) because of the extra expense, complexities of maintenance, and public ignorance in general. And frankly, the general public isn’t going to want to stop for gas and water-meth; they barely know how to put gas in the tank and drive the car as it is.

      I don’t know why it’s so difficult to get a new engine type to market. But look at Mazda and the Wankel and you’ll see the investment they made and the outcome … is anyone making new rotaries?

      Nope, any new engine type in the US will have to be Obama-approved before it can go to market. We need more windmills, and single-payer insurance. Oops, I digressed into why the economy is still in the doldrums after 7 years of brilliant leadership. The whole “blame Bush” think is a little too long in the tooth. Oops, I digressed again. Well, it’s all intertwined anyway.

  • avatar

    Just plain distilled water? Sounds easier to deal with than the Turbo Rocket Fluid used in the ’62-’63 Olds Jetfire, since you had to go back to the Olds dealer to buy that.

  • avatar
    Big Al from Oz

    Water augmentation of during the turbojet era (before turbofans) was used in hot and high airfield ops.

    During the initial phase of turbine engine implementation the lack of a power from turbojet engines was the norm, hence the eight engines required on the “average” sized B-52.

    During the 60s low bypass fans became the norm. This is the use of a two stage N1 (fan) and N2 (compressor). The fan worked as a supercharger to provide a reliable and steady source of air to the compressor, rather than the air being directly placed into the compressor.

    Fans also improved the compression ratio of jet engines by a large margin. Example, if you have a 4:1 compression ratio fan added to a 6:1 compression ratio compressor this gives you a 24:1 compression ratio.

    Heat increased as compression ratios rose and new materials were needed for the new fan engines as they ran much hotter.

    The fan augmented the compressor, just as the water augments the combustion.

    Water injection in cars will not last, just like in aviation. The automotive industry overall is several decades behind aviation, but it’s slowly catching up.

    • 0 avatar

      “The automotive industry overall is several decades behind aviation, but it’s slowly catching up.”

      This is absolutely not true. Automotive is way ahead in most, if not every area.

      • 0 avatar

        I don’t think it’s several decades behind, but please opine on why automotive is way ahead in most areas.

        To do that, first one must ask what is needed in cars that is also needed in airplanes? OK, interiors. If you go by the average 1980s Cessna or Piper (leaving transport aircraft out for the moment), interiors were worse in airplanes. But they were pretty shitty in cars back then, too.

        OK let’s see. Cars mostly don’t need wings. They don’t need retractable wheels. Oh, OK, engines! Well to compare engines in cars and airplanes is apples and oranges, my friend. Cars don’t climb from lea level to 30,000 feet in 15 minutes, cruise for hours in sub-zero temperatures using air thinner than Don Knotts’ hair then descending for landing back in survivable temperatures somewhere else. I guess we can’t make THAT comparison hold any water.

        OK then let’s see, how about navigation systems? Oh, are you seriously thinking nav systems in cars are more advanced than airplanes? The fanciest, most reliable GPS/infotainment system ever made for a car is a cassette-playing Sony Walkman in a world of smart phones when you compare aircraft navigation systems. So I guess that one is out.

        OK then suspension and handling. Well let’s see, airplane pretty much go in a straight line down a runway, take off, retract that gear, then land again in a straight line. Hard cornering isn’t needed like it is in cars. Oh, but there’s ABS in cars! Where did that tech come from? *scratching head* Oh, airplanes. Crap.

        Then there’s the whole manufacturing quality system and certified maintenance providers, recurrent training requirements for just about everyone in the business and you think cars are leap years ahead? I have a bridge I’d like to send you pictures of, my friend.

      • 0 avatar
        SCE to AUX

        Well, in support of Big Al from Oz, two examples would be anti-lock brakes and autopilot, which have been late to the car scene by decades.

        Of course, ground-based autopilot is much harder to implement.

        On the other hand, aviation is very conservative in its design approach since so many lives are at stake, which tends to slow progress sometimes.

        • 0 avatar

          Hmmm, aviation is very conservative because everything has to be built to a given specification, tested, sent through quality assurance and approved, then brought to market. It’s not the same as car stuff. You want to put a suicide knob on your steering wheel? Nobody can tell you no. But in aviation, yeah, there are people who can say no. it’s much more tightly controlled, tested and so on.

          And it’s not just airliners, although that’s where most of the money is spent. All sizes of airplanes have similar requirements, albeit different rules.

  • avatar

    I was figuring this concept could have possibly solved VW’s problem… until the increased emissions part of it came around.
    Does water injection work with diesel engines at all?

    Not that I really care so much about solving VW’s problems for them…

    If there were a way to harvest some of the water vapor from the exhaust, the water tank could just refill itself.

  • avatar

    Is that a Delta CV880?

  • avatar

    This sounds all backwards to me as water is normally a thing you don’t want anywhere near the combustion chamber. Or is the concept here more that the system uses pure steam (IE: water vapor = gas, not liquid) as that provides cooling plus expansion which are both good things. Any problems with rust? Or does using distilled water removed enough impurities that various parts will not corrode?

    • 0 avatar

      Sounds like a good scientific case to get all the hydrogen banned and removed from fuel molecules.

    • 0 avatar

      JMII, there a many issues to solve. For WM injection that is usually done at the intake track with an atomizer/injector. I believe there are even aftermarket systems, but having it managed by the ecu from the factory is a huge advantage.

      There is also a 6-stroke system that essentially ingests water that expands into steam to basically extract one more power stroke from the already hot cylinder. That system in theory would be a game changer in terms of efficiency, but there are several issues there that must be solved: effects on the oil system, perhaps new lubricants (or really old ones from the days of steam engines). And then there is the pesky issue of what to do with running that steam through the exhaust system and the impact on TWC operation and efficiency. It is a departure from the norm, but not exactly a moonshot either.

      I don’t know the specifics of why they need distilled water, but normal tap water contains many minerals and such all of which affects the quality of the water. My guess is that they don’t want hard water going through the injectors, cylinders, valves and various sensors. Much of north America doesn’t have the hard water that is very common in Europe so DW normalizes for that.

  • avatar

    Humid air is more dense than dry air. The water displaces molecules in the air, then cools the air (water-meth in airplanes, anyway) as it is injected into the engine’s intake. This increases air mass going into the engine and lowers engine temperatures. Lower engine temps, all things being equal, means you can introduce more fuel. More fuel (burning properly) = more power. And you can never have too much power in an airplane.

    And don’t forget atomization, methanol’s value as a fuel additive (it burns). There’s more to it but anyone interested can google it anyway. It’s nothing new.

    And the only time you have too much fuel is when you’re on fire. Ba dum DUM.

    • 0 avatar

      “Humid air is more dense than dry air.”

      Um, nope, it’s the other way around.

      On the other hand, spraying water into the intake charge tends to cool it off and increase the density because a lot of the water turns to vapor (vaporization absorbs heat).

      • 0 avatar

        I overspoke myself. Humidity in air displaces air molecules, as I said. The cooling effect results in a more dense air charge. So you know what I meant.

        Toss some methanol in there with its low flash point and you’ve done amazing things with the “routine” 15:1 mixture ratio.

  • avatar

    In the 70s I paid a $1 for water injection plans to hot rod my Chevy. Only problem was it required hypodermic needles that I couldn’t get without a perscription and I didn’t know any diabetics or heroin users.

  • avatar

    Nothing new here:

  • avatar

    if the jets are just injecting water, why is the exhaust so smoky and sooty?

    Unless the water lowers the flashpoint or whatever so that the burn is incomplete?

    That doesnt bode well for greenhouse gases or is it just particulate matter and it drops down anyway.

    • 0 avatar

      Look at today’s jets and you won’t see the thick smoke trails on takeoff like you do with the 707 and earlier generation of (especially non-fanjet) jet engines. Frankly, in commercial aviation anyway, water-meth has fallen out of use in modern engines. Development of new material alloys and more efficient combustion designs has all but eliminated the need for water meth on a routine basis.

      The one I worked with back in the day was the Rolls Royce 532 series that had a separate water meth tank in the nacelle. But those engines are dinosaurs; there is one in the Smithsonian in fact, near the front door of the aviation museum.

  • avatar

    It seems to me this has been around awhile. I’m hoping it works out this time. By my reckoning, this should also increase octane. No more premium?

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